I need some advice on how to get rid of scale on my sheffler

My shefflera has got scale on it and I don't know what methods that are available to get rid of it. I was told by my local feed and plant store to spray it once a week with mineral oil, but I don't think it's working. Can someone help me?

You can use horticultural oils that are marked "summer", "Perfect", or "All-Season", neem oil, or a systemic insecticide, like imidicloprid. The light hort oils work well when you follow directions.

Neem oil works well, but there is no immediate knockdown. It is effective both as a topical and a systemic insecticide. It is an anti-feedant, an oviposition deterrent (anti-egg laying), a growth inhibitor, a mating disrupter, and a chemosterilizer. It contains Azadirachtin, a tetranortriterpenoid compound that closely mimics the hormone ecdysone, which is necessary for reproduction in insects. When present, it takes the place of the real hormone and thus disrupts not only the feeding process, but the metamorphic transition as well, disrupting molting. It interferes with the formation of chitin (insect "skin") and stops pupation in larvae, thus short-circuiting the insect life cycle. It also inhibits flight ability, helping stop insect spread geographically. If you decide to use neem oil, use only pure, cold-pressed products (such as that packaged by Dyna-Grow) because they have the highest % of azadirachtin.

Easiest, and in my estimation - best, would be a product like Bayer Advanced 3-in-1 control for insects diseases and mites. It has the systemic insecticide imidicloprid, a systemic fungicide (tebuconazole), and the miticide taufluvalinate. It's approved for use on indoor plants but any spraying must be done outdoors. You can also purchase Imidicloprid as a 1.47% solution and use it as a soil drench by mixing 1 tsp with a liter of water and watering your plants with it 3 times at 2 week intervals.